70-80% = sporadic (just happens to people for no connected reason -no previous family history)

20-30% = familial

chance alone

genetic susceptibility

shared environment

combination

5-10% = inherited - this is what we are concerned about and can help you test for

BRCA1

BRCA2

other genes?

Genes and chromosomes

People -> genes -> nucleotides = CAGT

chromosomes = instruction manual

genes= instructions

amnio acids = words

nucleotides = letters

Two copies of every chromosome, every gene.

Dominant Inheritance (50%)

Cancer is actually caused by a change in a tumor suppressor gen*= they control cell growt*When both copies of the gene are changed (have a mutation) they cannot stop cell growth = tumor. (Two-hit hypothesis)